Since the early 1900s, most cars and trucks in the United States have been propelled using gasoline or diesel powered engines. In recent years, hybrid electric and pure electric powered vehicles have entered the fleet. There are two types of hybrids. One couples the power from the internal combustion engine to an alternator to charge the batteries and also to the drive train via mechanical ways. The batteries drive an electric motor which then also mechanically couples its power to the drive train. The alternative hybrid mechanism uses what is called the “locomotive” method. As in diesel locomotive engines, the fuel is used to generate electricity which then drives electric motors for powering the drive wheels.
Brazil has led the way in the use of neat ethanol powered vehicles. In France it is common to see gas stations offering liquefied petroleum gas (LPG) in addition to normal petroleum gasoline. The LPG is cryogenically stored at the delivery point and in the vehicle and the driver selects the traditional gasoline or the LPG. Countries from Turkey east to South Korea also use gasoline and liquefied natural gas (LNG) to power many of their vehicles.
In France, the vehicle has two tanks for the two different fuels. A user can merely turn a knob or switch to go from one fuel to the other. For both fuels, they are burned in a traditional internal combustion (IC) engine without the hybrid mechanism gaining momentum in North America.
There are research groups working on an approach using a compressed and non-combustible liquid/gas, such as liquid nitrogen, LN2. The expanded pressurized non-combustible gas is then used to drive a motor which is coupled to the drive wheels. One of the problems is frosting and icing due to energy required to compensate for the latent heat of vaporization. FIG. 1 shows a typical engine 100 powered by a compressed non-combustible liquid/gas. The engine 100 contains a fuel storage 102. A compressed and non-combustible liquid/gas 104 is stored within the fuel storage 102. By expanding the non-combustible liquid/gas 104 at a turbo expander or heat exchanger 106, a high pressure gas 110 is produced at the chamber 108. The high pressure gas 110 is used to propel a motor 112.
In all of the above instances, energy is extracted only once from the fuel, either by fuel combustion or the compressed inert gas.